Power utility companies use power distribution lines to carry power to customers spanning large geographic areas, typically from one or more power generating stations (or power plants) to residential and commercial customer sites. The power is carried on power distribution lines from the power plants at relatively high voltages and using alternating current (AC). Substations are commonly located near the customer sites to provide a step-down of the high voltage to a lower voltage (e.g., using transformers). Power distribution lines carry this lower-voltage AC from the substations to multitudes of customer sites at which endpoint (e.g., power-consumption metering) devices are installed to monitor and report on the power consumed at each site.
Power distribution systems can take on various different forms, oftentimes differentiated based on how the power distribution lines and the endpoint devices are used by the utility companies. One form of power distribution system, referred to as a power-line communication (PLC) system, has each of the multitudes of the endpoint devices configured to provide reports on the power consumed at each site by the endpoint devices transmitting this data back to the utility companies over the power lines. Another less-sophisticated type of power distribution system does not send data over the power lines (to/or from the endpoint devices), but rather relies on a meter reader to walk each customer site and manually read each such endpoint device in order to track the power consumed. Regardless of how the power distribution lines and the endpoint devices are being used and/or monitored, optimal system performance requires that the generated power being sent to each customer site reaches each site and is not interrupted.
Should power being provided to one or customer sites be interrupted, sometimes referred to as a power outage event, it is critical that the power utility companies (responsible for overseeing the power distribution) be informed promptly so that proper action and recourse can be taken to diagnose and correct the problem. In such outage events, however, the endpoint devices and/or the power lines are typically unavailable for use by the utility companies to discern which customer sites, or regions, have experienced the power interruption. Consequently, the utility companies often do not react in a timely manner and/or only in response to customers calling specified service centers to identify their location and complain of the outage events.
Given the importance of promptly knowing when power to customer sites have been interrupted and when power has been restored, various approaches have been developed to manage these power outage events. One of the more robust approaches has been implemented by the assignee of the instant disclosure (Landis+Gyr) in the form of an outage management system which uses power lines as part of the PLC systems for reporting back such events as a function of the power lines properly returned data from the endpoint devices installed at customer sites. Consider, for example, a multitude of endpoint devices scheduled at respective times to send (or transmit) power-meter data (each sending data once or twice per day) over the power lines for collection by the power-providing utility company. Should that scheduled data-transmission event, or expected strength of a received signal, not transpire as expected, a potential outage event can be detected. As another example, once a service team attempts to install power for the first time at a customer site or attempts to restore power after detection of a power-outage event, the service team waits to receive confirmation that the attempt has been successful by way of the endpoint device(s) being enabled once again to transmit the appropriate data over the power lines for collection as scheduled. Moreover, because such efforts to restore power are typically handled outside the customer-site facilities, once the efforts have been made to restore power, many such outage management systems have a difficult time discerning whether the efforts were successful from the perspective of the customers who are concerned with power being restored as a function of appliances operating once again inside the customer-site facilities. The delay and related costs involved with knowing when power to customer sites have been interrupted/restored, are significant.
Some of the more technically-robust outage management systems have implemented communications between customer sites through the use of mesh networks. In such mesh networks, layers of communication devices relay power outage information with communication connections being passed between adjacent communication devices, from the outermost layers towards the data collector device by way of nearby communication devices associated with the inner layers. This approach extends the communication reach of the outage management systems so as to reach customer facilities remotely located in the outermost layers of the network, and such systems can be implemented in a distributed manner so that there is no single point of failure. Moreover, when the outage event permits, this layer-to-layer communications approach can help to mitigate the above-discussed delays in terms of detecting outages and providing the service team with the needed confirmation. If, however, the outage event interrupts operation at any such communication device before the event data reaches an operative device at an inner layer, or the collector at the innermost layer, detection fails.
A related problem impacting both mesh-type and other outage management systems is the inability of such systems to promptly discern whether a power outage event is more likely isolated to a single or relatively small number of customer sites, more likely impacting an entire region of customer sites, or some situation in between these extremes. Discerning this type of information can be critical to deciding on what diagnosis/repair resources should assigned in order to promptly restore power.